Method of controlling plant growth



United States Patent 3,211,544 METHOD OF CONTROLLING PLANT GROWTHKenneth P. Dubrovin, Leawood, Kans., assignor, by mesne assignments, toGulf Oil Corporation, Pittsburgh, Pa., a corporation of Pennsylvania NoDrawing. Original application May 8, 1963, Ser. No. 278,974. Divided andthis application Sept. 21, 1964, Ser. No. 417,256

1 Claim. (Cl. 712.6)

This invention relates to novel chemical compounds, herbicidalcompositions containing these novel substances as active ingredients andto methods for controlling plant growth with such herbicidalcompositions. This application is a division of copending U.S.application Ser. No. 278,974, filed May 8, 1963. I

There are provided by this invention novel chemical compounds conformingto the general formula,

in which X is selected from the group consisting of 1 to 4 carbonalkyland chloroalkyl-substituents and Y and Z are selected from thegroup consisting of methyl-, chloroand chloromethyl-substituents locatedin positions on the phenyl ring selected from the group consisting ofthe 3,4- and 2,5-positions with respect to the point of attachment ofthe nitrogen atom.

The substituted cyclopropanecarboxanilide herbicides described above canbe formulated with inert carriers and with auxiliary agents such assolvents, penetrants, wetting agents, emulsifiers and the like toprovide herbicidal compositions that can be used efiectively to controlplant growth, particularly for selective post-emergent control.

The following examples are set forth to illustrate more clearly theprinciple and practice of this invention to those skilled in the art.

EXAMPLE 1 (a) Preparation of 4-chloro-Z-methoxybutyronitrile. Thiscompound was prepared by a procedure similar to that employed by Wilsonand Henze in J. Am. Chem. Soc., 63, 2112 (1941), for the preparation of4-chloro-1- ethoxybutyronitrile.

To 147 g. (1.1 mols) of silver cyanide dispersed in 300 ml. of anhydrousether was added a solution of 140 g. (0.98 mol) of1,3-dichloro-l-methoxy-propane in 250 ml. of anhydrous ether. Gentlerefluxing occurred during the addition. After addition was complete, theslurry was stirred overnight at room temperature. The resulting reactionmixture was then filtered, and the ether Was removed by distillation.The residue was then distilled to yield 78.1 g. of product boiling at 6769 C. at 8 mm. Hg pressure; n 1.4339.

(b) Preparation of methyl 4-chl0r0-2-meth0xybutyrate. A solution of 40g. (0.3 mol) of 4-chloro-2-methoxybutyronitrile in 80 ml. of methanolwas saturated with hydrogen chloride at room temperature and then wasrefluxed for 16 hours. The reaction mixture was poured into 150 ml. ofcold water, the organic layer was separated and the aqueous layer wasextracted with three small portions of ether to recover additionalproduct from the aqueous phase. The combined organic phases were3,211,544 Patented Oct. 12, 1965 dried and then distilled to yield 37 g.of product boiling at 93-96 C. at 18 mm. Hg; n 1.4359.

(0) Preparation of methyl 1-meth0vcycycl0pr0panecarboxylate.A mixture of34.8 g. (0.21 mol) of methyl 4-chloro-2-methoxy-butrate, ml. of benzeneand sodamide freshly prepared from 5.3 g. (0.23 g. atom) of sodium wasrefluxed for 36 hours. Suflicient water was added to the cold reactionmixture to dissolve the watersoluble constituents of the mixture and theorganic phase was separated, dried and filtered. So as to eflect removalof unsaturated by-products, the filtrate was reacted with small portionsof bromine dissolved in chloroform until reaction ceased, as indicatedby failure to cause disappearance of the bromine color. After removal ofbenzene by distillation at atmospheric pressure, the residue wasdistilled to yield 12 g. of colorless liquid product, B.P. 7780 C. at 43mm. Hg; 11 1.4294.

(d) Preparation of 3-4-dichloro-l-methoxycyclopropanecarboxanilide.-Aslurry of 17.9 g. (0.138 mol) of methyl1-methoxycyclopropanecarboxylate, 22.4 g. (0.138 mol) of3,4-dichloraniline, 9.0 g. (0.166 mol) of sodium methoxide and 210 ml.of benzene was stirred for 12 hours, during which time thebenzene-methanol azetrope was slowly removed by distillation. Themixture was cooled, then 50 ml. of water and 15 ml. of concentratedhydrochloric acid in 40 ml. of water was added. The organic phase wasseparated, extracted with dilute hydrochloric acid, then with water andthen dried and decolorized. After removal of benzene under reducedpressure, the residue was recrystallized from ligroin to yield 25 g. ofproduct, M.P. 89-91 C.

EXAMPLES 2 AND 3 5'-chl0ro-2-methyl 1 methoxycyclopropanecarboxanilideand 2',5-dichloro-1-methoxycyc1opropanecarboxanilide were prepared frommethyl l-methoxycyclocarboxylate and 5-chloro-2-methylaniline and2,5-dichloroaniline respectively, by essentially the same procedure asemployed in section (d) of Example 1 above.

The compounds of Examples 1, 2 and 3 were tested for post-emergenceherbicidal activity on a variety of plants, according to the proceduredescribed below.

An aqueous dispersion of the compound to be tested is prepared bycombining 0.4 gram of the substance with 4 ml. of a solvent mixture (3parts Emulphor EL-719 combined with one part xylene and 1 part kerosene)and then adding suificient water to make a total volume of 40 ml.Emulphor EL-719 is described as a polyoxyethylated vegetable oil.

Oats, wheat, soybeans, flax, millet, alfalfa, tomato and sugar beets areplanted in ordinary greenhouse potting soil in 4 inch pots which areplaced in the greenhouse. Ten to eighteen days after the emergence ofthe plants, they are sprayed at a rate of 5 pounds of active compoundper acre with the aqueous dispersions prepared according to the aboveprocedure in a total spray volume of 60 gallons per acre. Seven daysafter application the plants are observed and results noted according tothe following rating system:

C=Chlor0sis N=Necrosis G=Growth inhibition 0=no elfect 1=slight effect2=moderate effect 3=severe effect 4=maximum effect or dead plants poundis not completely soluble and to increase coverage by the activecompound. Emulsifying agents and wetting Table 1.Post-emergant activity(at application rate of lb./acre Oats Wheat Soy- Flax Millet AlfalfaTomato Sugar Overall beans Beets Activity Example 1 NlGl NlGl N2 4 4 N34 3 Example 2. 0 0 O 0 N2 0 0 0 1 Example 3. 0 0 0 0 0 0 Thepre-emergence activity of the herbicidal agents of Examples 1, 2 and 3was tested according to the following procedure:

Oats, soybeans, radish, flax, millet, alfalfa, sugar beets, bromegrass,cotton, coxcomb, corn and crabgrass are seeded in sandy soil ingreenhouse flats.

Approximately 3 parts of active ingredient are dissolved in 2000 partsof acetone as inert carrier. The seeded flats are sprayed with thissolution at the rate of pounds of active compound per acre and areplaced in the greenhouse. After 21 days the treated flats are examinedand the results noted according to the same rating system used above.These results are shown in Table 2.

agents, also known as surface active agents, are sold under numeroustrade marks and may be either pure com pounds, mixtures of compounds ofthe same general group, or they may be mixtures of compounds of different classes.

There are thus also provided by this invention novel herbicidalcompositions containing one or more of the describedcyclopropanecarboxanilides intimately dispersed with or dissolved in asurface active agent. Typical satisfactory surface active agents whichmay be used are the alkali metal higher alkylarylsulfonates such assodium dodecylbenzenesulfonate and the sodium salts ofalkylnaphthalenesulfonic acids, fatty alcohol sulfates such as thesodium salts of the monoesters of sulfuric acid with Table 2Pre-emergentactivity (at application rate of 10 lb./ acre) Soy- Sugar Brome Gox-Crab- Oats beans Radish Flax Millet Alfalfa Beets Grass Cotton comb Corngrass N3 01 G2 N4 N4 N4 N4 N4 N4 G2 N4 N4 N4 N2 03 N4 N4 N4 N4 N4 N3 N4N4 0 N4 Example 3- 0 0 0 0 0 0 0 0 0 0 0 N2 Upon examination of the datapresented in Tables 1 and 2, it will be seen that the compound ofExample 1 shows both high post-emergent and pre-emergent activity. Atproper application levels this substance possesses .utility in thecontrol of weeds in cotton. The compound of Example 2 shows utility inthe control of weeds in corn. The compound of Example 3 possessesutility in the control of crabgrass.

The 1-alkoxycyclopropanecarboxanilides of the present invention showgood activity against a number of plant species. They also show betterselectivity against a number of closely related species than is usuallyobserved with compounds having such a high degree of activity. Theselectivity of kill can be enhanced by proper formulation and control ofapplication rates. alkoxycyclopropanecarboxanilides have a high degreeof resistance to most of the common soil microorganisms and, when usedas pre-emergent herbicides, provide a high degree of control over anextended period of time.

The excellent herbicidal activity of the cyclopropanecarboxanilides ofthis invention requires the application of only small amounts of theactive ingredient distributed uniformly over a wide area. Of course,this is difficult to do employing the pure material. However, byincreasing the bulk of the material, such as by mixing the compound withan inert diluent or carrier, the application to growing plants and soilcan be achieved more readily. Such carriers may be either solids, suchas talc, clay, diatomaceous earth, sawdust, calcium carbonate or thelike, or liquids such as water, kerosene, acetone, benzene, toluene,xylene, and the like, in which the active compound may be dissolved ordispersed.

Emulsifying agents preferably are used to achieve a suitable emulsion ordispersion in liquids such as water to give aqueous sprays. Emulsifyingagents and wetting agents may also be used to aid in dispersing theactive compound in liquids used as the carrier in which the com- The 1-n-aliphatic alcohols containing about eight to eighteen carbon atoms,long chain quarternary ammonium compounds, sodium salts of petroleumderived alkylsulfonic acids, polyethylene sorbitan monooleate,alkylarylpolyether alcohols, water-soluble lignin sulfonate salts,alkalicasein compositions, long chain alcohols usually containing aboutten to eighteen carbon atoms, and condensation products of ethyleneoxide with fatty acids, alkylphenols or mercaptans.

Other additives such as a lanolin or kerosene emulsion, or Tween-20 (aproduct described as sorbitan monolaureate polyoxyalkylene derivative),stickers and other auxiliary materials may be included in solid orliquid formulations to increase coverage of the active compound. Thesematerials are also considered to be surface active agents.

The cyclopropanecarboxanilides of the invention can be used asherbicides at application rates of from about 20 pounds to as little asabout 0.1 pound per acre. When the compounds are used as a pre-emergentherbicide, an application rate of about 0.5 to about 20 pounds per acreis normally used, with about 2 to about 10 pounds per acre beingpreferred. When they are used as a postemergent herbicide, anapplication rate of about 0.01 to 20 pounds of one or more activecompound per acre is used, with an application rate of about 0.1 to 3pounds per acre being preferred. When using a water emulsion of theherbicide, a spray volume of about 1 to about gallons of aqueousemulsion, and preferably about 5 to 40 gallons, per acre is used.

The above descriptions and particularly the examples are set forth forpurposes of illustration only. Many variations and modifications thereofwill be obvious to those skilled in the art and can be made withoutdeparting from the spirit and scope of the invention herein described.

What is claimed is:

The method of controlling plant growth which comprises applying to thelocus of the plant a herbicidal quantity of a cyclopropanecarboxanilideconforming to the formula lected from the group consisting of the 3,4-and 2,5-positions with respect to the point of attachment of thenitrogen atom.

References Cited by the Examiner UNITED STATES PATENTS 2,490,756 12/49Kenyon et a1. 260562 X 2,654,722 10/53 Young et al. 260562 X 2,692,28210/54 Brown 260-557 2,723,192 11/55 Todd 712.6 2,726,150 11/55 Wolter71-2.6 3,110,729 11/63 Greene et al 260557 JULIAN S. LEVITT, PrimaryExaminer.

